The overall aim of this thesis was to investigate postural balance, physical activity, physical capacity and their associations in young people (16-20 years) with intellectual disability (ID), mild to moderate. The aim was also to study the reliability and concurrent validity of postural balance tests.

To evaluate postural balance, one assessor used five common postural balance tests and one new test. The tests were performed twice for 89 young people with ID (one to twelve days apart). Intraclass correlation coefficients greater than 0.80 were achieved for four of the common balance tests: Extended Timed Up and Go Test (ETUGT), Modified Forward Reach Test (MFRT), One-Leg Stance Test (OLS), and a Force Platform Test (FPT). The smallest real difference ranged from 12% to 40%; less than 20% is considered to be low. For the six balance tests, the concurrent validity varied between none to low.

Falls are more common for young people with ID compared to young people without ID. One reason could be impaired postural balance. The postural balance for young people with ID has not been thoroughly investigated. Therefore, five balance tests and three muscle strength tests were used to compare young people with ID with an age-matched control group without ID (n=255). The young people with ID had significantly lower scores on most of the postural balance tests and muscle strength tests of the trunk and lower limbs. Muscle strength, height, and body mass index had no strong association with postural balance. The results also illustrated that young people with ID did not rely more on vision for their balance ability compared to peers without ID.

It seems that postural balance is impaired for young people with ID when evaluated with common tests. An everyday situation is to react to unexpected balance disturbances to avoid falls by using different postural responses. Since young people with ID seem to fall more often than peers without ID, it is valuable to investigate if those postural responses are different between the groups. Therefore, young people with and without ID (n=99) were exposed to six backward surface translations and several postural muscle responses were evaluated: muscle synergies and strategies, muscle onset latency, time-to-peak amplitude, and adaptation. The responses of the investigated muscles – the gastrocnemius, the biceps femoris, and the erector spinae L4 level – were measured using electromyography. The results showed that there were no differences between the two groups with respect to synergies or strategies, muscle onset latency, and time-to-peak amplitude. An overall pattern was seen, that young people with ID adapted their muscle response slower in all three muscles than peers without ID, but this pattern was not statistically significant.

Studies have shown that people with ID have impaired postural balance, a lower level of physical activity, and lower aerobic capacity compared to people without ID. The association is however not investigated. Therefore, postural balance (postural sway indirectly measured with the subjects standing on a force platform), physical activity (measured with a pedometer), and aerobic capacity (measured with a sub-maximal ergometer cycle test) were used to assess young people with and without ID (n=106). To investigate the subjects’ view of their own health, the subjects completed an adapted questionnaire that addressed their perceived health. The analysis showed no significant associations between postural balance, level of physical activity, and aerobic capacity. The subjects in the ID group, both men and women, had significantly lower aerobic capacity compared to subjects without ID. The answers from the health questionnaire did not correspond to the measured outcomes from the physical tests for young people with ID.

In conclusion, ETUGT and MFRT can be used to evaluate change in postural balance over time in young people with mild to moderate ID. The low concurrent validity suggests that the postural balance tests probably challenge various subsystems. Young people with ID have impaired postural balance and perform lower on muscle strength tests than age-matched controls. Postural muscle responses after external perturbations seem to be similar for young people with and without ID, but the ability to adapt muscle responses after repeated perturbations appears to be slower for young people with ID. The studies in the thesis also indicate that young people with ID have reduced level of physical activity and lower aerobic capacity. The lack of association between the different physical functions indicates that they should be evaluated and exercised separately. Young persons with ID might have more difficulty realising the health advantage of being physically active, as they do not seem to make this connection. Because of this, it is important that parents/guardians, school staff, physiotherapists, and others encourage them to participate in physical activity.

To improve current understandings of physical Workload (WL) in elite Bandy, ten bandy players were monitored for heart rate (HR) during thirteen matches over one championship season. Participants were divided into five subgroups according to playing position - libero, defender, halves, midfielder and forward. HR measurements were analyzed with two different methods to compute physical WL - (i) percentage of total time spent in different HR zones (HRres) and (ii) WL based on the Edwards method. Also determined was the time spent at HR levels above the lactate threshold (LT). A one-way ANOVA was used for analysis. For WL according to the Edwards method, significant differences (p=0.05) were shown between groups with defenders presenting the highest scores and forwards and liberos the lowest. A significant difference (p=0.05) was found between liberos and halves and the other positions as to how much time they spent in zone 70-80% of HRres. In 91-100% of HRres there was a distinct difference between defenders and the other positions and also forwards differed significantly from liberos, defenders and halves (p=0.05). The libero spent only one percent of the time over the LT, whereas the midfielder spent about 27% of the time over the LT. Overall, defenders showed the greatest WL during a match and liberos the lowest. The practical implications of these findings can help coaches and trainers design training methods specific to each position as well as individualized training sessions for each player in elite bandy.

For adolescent people with ID, falls are more common compared to peers without ID. However, postural balance among this group is not thoroughly investigated. The aim of this study was to compare balance and muscle performance among adolescents aged between 16 and 20 years with a mild to moderate intellectual disability (ID) to age-matched adolescents without ID. A secondary purpose was to investigate the influence of vision, strength, height and Body Mass Index (BMI) on balance. A group of 100 adolescents with ID and a control group of 155 adolescents without ID were investigated with five balance tests and three strength tests: timed up and go test, one leg stance, dynamic one leg stance, modified functional reach test, force platform test, counter movement jump, sit-ups, and Biering-Sørensen trunk extensor endurance test. The results showed that adolescents with an ID in general had significantly lower scores in the balance and muscle performance tests. The group with ID did not have a more visually dominated postural control compared to the group without ID. Height, BMI or muscle performance had no strong correlations with balance performance. It appears as if measures to improve balance and strength are required already at a young age for people with an ID.

Hälsa är en förutsättning för att kunna förverkliga sina mål i livet. Personer med utvecklingsstörning, cirka 90 000 i Sverige, har nedsatt hälsa jämfört med personer utan utvecklingsstörning och det leder till att denna grupp har svårare att uppfylla sina mål. Personer med utvecklingsstörning drabbas i större utsträckning av övervikt, typ 2-diabetes, hjärt- och kärlsjukdomar, högt blodtryck, benskörhet och depression. Undersökningar visar också på nedsatt fysisk aktivitet, motorik, syreupptagningsförmåga, muskelstyrka och postural balans hos denna grupp. Dessa sjukdomar och nedsatta förmågor går att påverkai positiv riktning med fysisk aktivitet. Fysioterapeuter som har bred kunskap om hälsa och anpassning av fysisk aktivitet kan vara till stor hjälp vid prevention, bedömning och träning.

This study tests the concurrent validity and test–retest reliability of a new functional balance test – the Dynamic One Leg Stance (DOLS) in blind subjects and sighted, blindfolded subjects. Twelve blind and 12 sighted men and women between 19 and 61 years volunteered to participate. The correlation between DOLS and the commonly used One Leg Stance balance test (OLS) and the force platform test (FPT) was tested for both the right and left leg. The test–retest reliability of DOLS was analysed using three measurements at least 2 h apart. The correlation between DOLS and FPT and between DOLS and OLS for blind subjects was −0.13 (n.s.) and 0.77 for the left leg and −0.78 and 0.89 for the right leg. For blindfolded subjects, the correlations were −0.56 (n.s.) and 0.93 for the left leg and −0.61 and 0.71 for the right leg. The weighted Kappa values for DOLS were between 0.47 and 0.88 for blind subjects and between 0.47 and 0.72 for blindfolded subjects. Based on these findings, DOLS appears to be a fairly valid and reliable balance test for subjects with vision loss, acquired and experimental. However, further tests of DOLS are necessary.

Background: Impaired balance leading to falls is common in the older adults, and there is strong evidence that balance training reduces falls and increases independence. Reduced resources in health care will result in fewer people getting help with rehabilitation training. In this regard, the new technology augmented reality (AR) could be helpful. With AR, the older adults can receive help with instructions and get feedback on their progression in balance training. The purpose of this pilot study was to examine the feasibility of using AR-based visual-interactive tools in balance training of the older adults.; Methods: Seven older adults (66-88 years old) with impaired balance trained under supervision of a physiotherapist twice a week for six weeks using AR-based visual-interactive guidance, which was facilitated through a Microsoft HoloLens holographic display. Afterwards, participants and physiotherapists were interviewed about the new technology and their experience of the training. Also, fear of falling and balance ability were measured before and after training.; Results: Five participants experienced the new technology as positive in terms of increased motivation and feedback. Experiences were mixed regarding the physical and technical aspects of the HoloLens and the design of the HoloLens application. Participants also described issues that needed to be further improved, for example, the training program was difficult and monotonous. Further, the HoloLens hardware was felt to be heavy, the application's menu was difficult to control with different hand manoeuvres, and the calibration took a long time. Suggestions for improvements were described. Results of the balance tests and self-assessment instruments indicated no improvements in balance performance after AR training.; Conclusions: The study showed that training with the new technology is, to some extent, feasible for the older adults, but needs further development. Also, the technology seemed to stimulate increased motivation, which is a prerequisite for adherence to training. However, the new technology and training requires further development and testing in a larger context.

Cross-country skiing is a fast-paced, a cognitively demanding, and a popular sport within international organizationsincluding athletes with intellectual impairment (II); however, research on how the level of II affects skiing performanceis limited. The aim of this exploratory study was to compare differences in the overall performance (segment time and racetime) and gear selection between a sample of cross-country skiers with II (n¼22) and a control group of skiers without II(n¼12), during a competitive 10 km freestyle race. The groups were matched on training background and skiing level basedon interviews with coaches and trainers. The independent samples t-test revealed a higher velocity in the first segment forthe control group (6.100.62 m/s) compared to the skiers with II (5.500.56 m/s; p<0.05), but no significant differencesin total race time between the groups. With respect to their ability to effectively select gears during the races, there was asignificant difference between the groups, where the pattern was that skiers with II used a lower gear compared to theskiers without II and that pattern became even more apparent towards the second half of the race. These findings supportthe assumption that impaired cognitive function may constrain the ability to optimally select the appropriate gear infunction of the characteristics of the skiing track, which is a key determinant of skiing performance.

Background The influence of various physical exercise frequencies on postural balance and muscle performance among young persons with intellectual disability (ID) is not well understood.

Method Cross-sectional data from 26 elite athletes were compared with 37 students at a sports school and to 57 students at a special school, all diagnosed with mild to moderate ID and with different exercise frequencies. Data were also compared with a group of 149 age-matched participants without ID.

Results There were no significant differences in postural balance between young ID groups regardless of physical exercise frequency, all of them had however impaired postural balance compared to the non-ID group. The group with high exercise performed better than the other ID groups in the trunk muscle endurance test.

Conclusions It appears as if physical exercise frequency don’t improve postural balance but endurance in the trunk muscles for young persons with ID.

Previous studies show that people with intellectual disability (ID) appear to have impaired postural stability, a lower level of physical activity, and lower aerobic capacity compared to persons without ID, limitations that could affect their health. This study investigates these physical functions and their associations in a group of young people with ID compared to an age-matched group without ID. In total, this cross-sectional study included 106 high school students (16-20 years): 57 students with mild to moderate ID and 49 age-matched students without ID (control group). Tests were performed for postural stability, level of physical activity, and aerobic capacity. Both females and males with ID had significantly lower estimated maximum oxygen uptake (l O2/min) (p< 0.001 for females and p=0.004 for males) and a lower aerobic capacity expressed relative to body weight (ml O2/ kg*min) (p< 0.001 for females and p=0.012 for males) compared to age-matched peers. Analyses of associations were made using the Pearson’s correlation coefficient and multivariate linear regression analysis. No significant associations could be found. Physical status appears impaired for young people with ID and functions, such as postural stability, should be evaluated separately.

This study examines postural muscle responses to backward perturbations in young people (16-20 years) with and without intellectual disability (ID). The study included 56 young people with ID and 43 age-matched without ID volunteers. The subjects stood on a platform that was moved backwards in a surface translation. Lower and upper leg muscles and lower back spine muscles were recorded with surface electromyography (EMG). Muscle onset latency, time to peak amplitude (EMG), adaptation of muscle responses to repeated perturbations (using integrated EMG (IEMG) for epochs), and synergies and strategies were assessed. The result showed no differences between the two groups in muscle onset latency, synergies, and strategies. Young people with ID reduced their time to peak amplitude in investigated muscles, a response that was different from the group without ID. Also, young people with ID tended to adapt their IEMG less compared to the controls. These findings suggest that young people with ID have limited ability to use somatosensory information and adapt their postural muscle responses to repeated external perturbations.

OBJECTIVES:

Some studies have reported that people with intellectual disability may have reduced balance ability compared with the population in general. However, none of these studies involved adolescents, and the reliability and validity of balance tests in this population are not known. The purpose of this study was to examine the reliability of six different balance tests and to investigate their concurrent validity.

DESIGN:

Test-retest reliability assessment.

SETTINGS:

All subjects were recruited from a special school for people with intellectual disability in Bollnäs, Sweden.

PARTICIPANTS:

Eighty-nine adolescents (35 females and 54 males) with mild to moderate intellectual disability with a mean age of 18 years (range 16 to 20 years).

INTERVENTIONS:

All subjects followed the same test protocol on two occasions within an 11-day period.

MAIN OUTCOMES:

Balance test performances.

RESULTS:

Intraclass correlation coefficients greater than 0.80 were achieved for four of the balance tests: Extended Timed Up and Go Test, Modified Functional Reach Test, One-leg Stance Test and Force Platform Test. The smallest real differences ranged from 12% to 40%; less than 20% is considered to be low. Concurrent validity among these balance tests varied between no and low correlation.

CONCLUSION:

The results indicate that these tests could be used to evaluate changes in balance ability over time in people with mild to moderate intellectual disability. The low concurrent validity illustrates the importance of knowing more about the influence of various sensory subsystems that are significant for balance among adolescents with intellectual disability.

Hur man använder denna bästa-praxishandbokInnehållet i handboken grundar sig på en övergripande och djupgående granskning av de resurser som för närvarande finns tillgängliga för den här särskilda formen av handledning. Efter att ha gjort omfattande sökningar på webb och i databaser, har över 100 resurser som bl.a. omfattar träningshandböcker, kurser (bl.a. e-lärande), läroböcker, artiklar, webbsidor och informationsbroschyrer kunnat lokaliseras. Var och en av dessa har granskats och information som kan vara till nytta när det gäller att träna idrottare med IF har använts. Vissa resurser har vi inte kunnat ta med eftersom de inte var skrivna på engelska, men de lades till i databasen. Vi har också intervjuat tränare och idrottare med kunskaper om olika idrottsgrenar för att utnyttja deras erfarenheter, exempel och resurser för att ytterligare utvidga dessa idéer om bästa praxis. Därefter har vi placerat dessa förslag i en teoretisk ram för att hjälpa tränarna att generalisera verksamheten i olika sammanhang. 

Målgruppen för denna handbok för bästa praxis är tränare som håller på med eller är intresserade av att handleda idrottare med IF – alltifrån gräsrötter till elitnivå. Den kan också komma väl till pass för gymnastiklärare, frivilliga som arbetar med personer med IF, arrangörer eller personer som ordnar med idrotts- och motionstillfällen. Informationen i handboken kan också vara till nytta för föräldrar eller vårdnadshavare till barn/unga personer med IF som vill engagera sig inom idrotten, både som rekreations- och som utvecklingsinriktad verksamhet.

Handboken fokuserar på flera huvudsakliga träningsområden för idrottare med intellektuell funktionsnedsättning.  

BACKGROUND: The Para athletics wheelchair-racing classification system employs best practice to ensure that classes comprise athletes whose impairments cause a comparable degree of activity limitation. However, decision-making is largely subjective and scientific evidence which reduces this subjectivity is required.

AIM: To evaluate whether isometric strength tests were valid for the purposes of classifying wheelchair racers and whether cluster analysis of the strength measures produced a valid classification structure.

METHODS: Thirty-two international level, male wheelchair racers from classes T51-54 completed six isometric strength tests evaluating elbow extensors, shoulder flexors, trunk flexors and forearm pronators and two wheelchair performance tests-Top-Speed (0-15 m) and Top-Speed (absolute). Strength tests significantly correlated with wheelchair performance were included in a cluster analysis and the validity of the resulting clusters was assessed.

RESULTS: All six strength tests correlated with performance (r=0.54-0.88). Cluster analysis yielded four clusters with reasonable overall structure (mean silhouette coefficient=0.58) and large intercluster strength differences. Six athletes (19%) were allocated to clusters that did not align with their current class. While the mean wheelchair racing performance of the resulting clusters was unequivocally hierarchical, the mean performance of current classes was not, with no difference between current classes T53 and T54.

CONCLUSIONS: Cluster analysis of isometric strength tests produced classes comprising athletes who experienced a similar degree of activity limitation. The strength tests reported can provide the basis for a new, more transparent, less subjective wheelchair racing classification system, pending replication of these findings in a larger, representative sample. This paper also provides guidance for development of evidence-based systems in other Para sports.

Fatigue is a phenomenon of pronounced importance in sports. Recently, there is strong evidence of interplay between the prefrontal cortex and motor output during fatiguing contractions. The dorsolateral prefrontal cortex (DLPC) due to its large involvement in cognitive and motor activities is believed to be involved but this requires physiological clarification. AIM: We investigated the relationship between DLPC activity - responses in oxyhemoglobin (HbO2) and total hemoglobin (HbT) measured by near-infrared spectroscopy (NIRS), and the vastus lateralis muscle (VL) activity - quantified as root-mean-square (RMS) of the EMG signal, during a fatigue protocol.

METHODS: Four male runners (32±12 yrs) with probes for NIRS over the DLPC and EMG over the VL performed a track running test at a constant speed to fatigue (exhaustion). The running speed was individually determined as the average speed of a 1200-m time trial performed ~3 days prior to testing. For NIRS changes in μmole/L of HbO2 and HbT were computed. The VL EMG-RMS of the contraction of each step was normalized as a percent of a submaximal reference contraction (%RMS), thus removing the non-activity between steps. Data of 10s epochs at 20, 40, 60, 80 and 100% of time for each lap were averaged for analyses. Regression analyses performed with HbO2 and with HbT as dependent variables and %RMS as the independent variable.

RESULTS: Over time there was an increase in HbO2 and HbT in the DLPC, and in VL-%RMS. Both HbO2 and HbT correlated strongly with EMG-RMS during running to fatigue (see figures below); p<0.001 for both.

CONCLUSION: The strong relationship between DLPC and VL activities during running to fatigue suggests the involvement of the DLPC in the central processing of fatigue.

Profiles of physical workload in sports are useful to optimize performance and reduce the risk of injury. The aim of the study was to investigate physical workload in 10 elite bandy players by describing acceleration, deceleration, and high-intensity skating during bandy match-play. During 13 home matches, 10 male elite bandy players wore a GPS unit to measure changes in the total distance, total distance skating in two speed zones, and total distance of acceleration and deceleration. A within-subject design was used to measure changes over time during match-play by comparing first and second halves as well as comparisons for consecutive 15 min intervals. No significant differences were observed for high-intensity or very high-intensity acceleration and deceleration for comparisons by halves or for 15-min intervals. For comparisons by halves, a significant time-dependent effect was observed on very fast skating (1337.6 m vs. 1160.9 m), sprint skating (300.0 m vs. 272.0 m), low-intensity acceleration (342.7 m vs. 333.0 m), and total distance covered (10,916.9 m vs. 10,450.3 m). These variables, along with low-intensity deceleration, were also significant for the 15 min interval comparisons. The results show that there is no time-dependent reduction in high-intensity acceleration and deceleration in elite bandy match-play. However, elite bandy players do not maintain the distance of high-intensity skating throughout a whole match.

Background: Postural balance training is primarily used by athletes as rehabilitation after previous injuries or for prevention. A few studies have been made with the aim of investigating whether postural balance training can improve other physical functions in healthy participants. However, there is no consensus regarding effects.

Objective: The aim of this study was to investigate whether postural balance training can improve muscle function in healthy adult athletes.

Method: Seventeen healthy adult (6 males and 11 females) athletes between the ages of 21 and 50 years performed three postural balance exercises once a day 3x30 seconds per exercise on each leg. This intervention was performed daily for six weeks. Their muscle function were assessed with squat jump, heel rise and grip strength (control). Evaluation was done before and after the training period.

Results: Jump height, number of repetitions in heel rise and duration in standing on one leg increased with statistical significance. There were no improvements in postural sway and grip strength.

Conclusion: The results suggest that a postural balance training period can provide a better local muscle function regarding explosive strength and endurance among adult athletes even if postural sway is not affected.

Purpose: This study examined the physiological sport-specific demands (total distance, mean velocity, effective game time, and time in five velocity zones) in elite bandy players of offensive and defensive playing positions. Method: Data were collected with 10 Hz GPS-units in the Swedish Elite League during the season 2015/16. Ten male elite bandy players were examined during 13 matches. Data were analyzed with Independent Samples Test and with descriptive statistics. Result: Analysis showed that defensive positions covered a significantly longer (p < .001) total distance (23.2 ± 2.4 km vs 21.1 ± 3.5 km) compared to the offensive positions. Significantly higher (p < .001) mean velocity was found in offensive positions (17.8 ± 1.0 km/h vs 15.5 ± 1.6 km/h) in relation to defensive positions. In variable effective game time analysis exposed significant differences (p < .001) between offensive positions and defensive positions (90.4 ± 3.5 min vs 71.3 ± 11.9 min). Furthermore, in easy and moderate skating defensive positions spent significantly (p < .001) more time and in fast, very fast, and sprint skating offensive positions spent significantly (p < .001) more time in relation to each other. The descriptive analysis of positions indicates that libero, defender, and half have the longest game time, half skate the longest distance, and forward have the highest mean velocity during the game. Conclusion: From a practical perspective, the result can provide coaches knowledge when planning the setup in training drills. Thus, the training sessions could be more specific to the playing position, which could maximize the player's physiological outcome in order to optimize performance.

Introduction: A well-functioning anti-doping system relies on being perceived by athletes as effective, fair, and practically feasible to implement. While research has highlighted the views of Olympic athletes on anti-doping over the past decade, the experiences and perceptions of Para athletes have not been extensively explored. The purpose of this study was to examine Swedish elite Para athletes' experiences and perceptions of the policy and practice of the anti-doping system.

Methods: A quantitative cross-sectional approach was used, with a web survey elaborated from a survey with Olympic athletes adjusted for Para athletes with physical, visual, and intellectual impairments. The sample consisted of 66 active Para athletes competing at national or international level (response rate 71%). Data were analyzed using descriptive statistics and differences between subgroups were examined Fisher's exact test. Thematic analysis was employed to analyze open-ended questions.

Results: Most of the respondents expressed a positive outlook on the anti-doping system, advocating for comprehensive efforts. A significant portion (35%) had not received anti-doping education, with those who did reporting increased confidence in avoiding unintentional doping. Despite their elite status, half of the respondents had not undergone doping control. Mistrust regarding the system's effectiveness and fairness was identified, with over half of the participants emphasizing the need for new technical solutions to enhance procedures specifically tailored for Para athletes.

Discussion: The athletes in this study advocate for a Para sports-focused approach in the anti-doping system, emphasizing equal testing opportunities, procedural adjustments for independence and privacy, and increased access to education. The findings illuminate the unique conditions faced by athletes with impairments within the anti-doping system, offering valuable insights for policymaking in the development of anti-doping strategies tailored to Para athletes and their various impairments.

Background

As physical activity can prevent overweight and promote general health, the aim was to investigate the amount of physical activity among adolescent and young adult women and men with intellectual disability (ID), compared to age-matched control groups without intellectual disability. A further aim was to examine whether physical activity level was associated with the body mass index (BMI).

Materials and methods

Fifty-two adolescent and young adult women and men with intellectual disability and 48 without intellectual disability, between the ages 16 and 20 years, BMIs ranging from 16.3 to 50.3 kg/m2, were measured for number of steps taken with a pedometer for five consecutive days (Sunday–Thursday).

Results

The only group to meet recommendations regarding number of steps (10 000–12 000/day) was women without intellectual disability. No significant associations were found between total number of steps taken and BMI.

Conclusion

As the majority of adolescents and young adults with intellectual disability, especially women, did not reach recommended activity levels regardless of their BMIs, this call for broad measures to increase physical activity.